Oscillating mechanism for tennis ball throwing machine

ABSTRACT

A BALL THROWING MACHINE HAVING A TWO-SECTION SUPPORT INCLUDING A FIXED LOWER SECTION AND A MOVABLE UPPER SECTION WHICH CARRIERS THE BALL THROWING MECHANISM. A MOTORDRIVEN CAM FOLLOWER ASSEMBLY IS PROVIDED ON THE UPPER MOVABLE SECTION AND COOPERATES WITH A CAM ASSEMBLY ON THE FIXED LOWER SECTION SO AS TO BIAS THE ROTATABLE UPPER SECTION WITH RESPECT TO THE FIXED SECTION AND CAUSE THE BALL THROWING MECHANISM TO MOVE ANGULARLY. THE CAM FOLLOWER ASSEMBLY IS SPRING BIASED INTO ENGAGEMENT WITH THE CAM ASSEMBLY. A LIMIT STOP IS PROVIDED TO LIMIT THE DEGREE OF RETURN OF THE CAM FOLLOWER ASSEMBLY.

Aug. 6, 1974 F EARLE JR" ETAL Re. 28,096

OSCILLATING MECHANISM FOR TENNIS BALL THROWING MACHINE Original FiledSept. 5, 1968 5 Sheets-Sheet 1 '!!Ilu|| W N 0 I8 Fred A. Ear/e, Jr. Carl5. Pound INVIENTORS A name Aug. 6, 1974 EAR-L5 JR" ETAL Re. 28,096

OSCILLATING MECHANISM FOR TENNIS BALL I'HROWTNG MACHINE Original FiledSept. 5, 1968 6 Sheets-Sheet 2 Fred A. Ear/e, Jr. Carl 5. PoundINVENTORS 3 F1 WM Hm Aug. 6, 1974 k EARLE, JR ErAL Re. 28,096

OSCILLATING MECHANISM FOR TENNIS BALL THROWTNG MACHINE 6 Shoots-Sheet 5Original Filed Sept. 5, 1968 50 Fig 5 58 56 J 54 36 64 Imam 68 4a 70Fig. 6

l 7/ 46 Fred A. Ear/e, J!-

Car/ 5. Pound IN "ENTORS ,HlllllllllIll|!i !lIII IIIHIIIIIIII' UnitedStates Patent Int. Cl. F411) 3/04 US. Cl. 124-1 20 Claims Matterenclosed in heavy brackets appears in the original patent but forms nopart of this reissue specification; matter printed in italics indicatesthe additions made by reissue.

ABSTRACT OF THE DISCLOSURE A ball throwing machine having a two-sectionsupport including a fixed lower section and a movable upper sectionwhich carries the ball throwing mechanism. A motordriven cam followerassembly is provided on the upper movable section and cooperates with acam assembly on the fixed lower section so as to bias the rotatableupper section with respect to the fixed section and cause the ballthrowing mechanism to move angularly. The cam follower assembly isspring biased into engagement with the cam assembly. A limit stop isprovided to limit the degree of return of the cam follower assembly.

Heretofore, machines designed to throw tennis balls for the purpose ofpracticing the return thereof, have been unable to automatically throwthe ball at varying angles relative to the previous throw. Thosemachines that did have the capability to angle the shot had to be donemanually prior to the release of each shot, and therefore, required anattendant to angle each shot if such was desired. As a result, unlessthe machine was attended by someone to angle the shot the machineprovided no more variety nor practice than the volleying of a ballagainst a retaining wall.

The instant invention relates to a device to convert a tennis ballthrowing machine to automatically vary each shot by angularly displacingit from the preceding shot. This sequence of varying shots from one sideof the court to the other is more nearly an actual simulation of gameplay than has been heretofore available. The device is easily adapted toany existing tennis ball throwing ma chine and has a cam and returnmechanism therefore which angles each shot relative to the previous shotwith any predetermined angle desired. The speed of the camming action isvariable to coincide with any speed of ball thrown by the machine. Thedevice therefore, when installed on a tennis ball throwing machineprovides a versatility therein which cannot be duplicated in any othertraining machine.

It is therefore an object of this invention to provide a simple butunique device that automatically varies the angle of a ball thrown by atennis ball throwing machine.

It is a further object of this invention to provide a device thatenables a tennis ball throwing machine to automatically vary the angleof delivery of successive thrown balls from a tennis ball throwingmachine.

It is a still further object of this invention to provide a device thatautomatically angles the successive shots of a tennis ball throwingmachine with capability to compensate for the speed of the thrown balls.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter deice scribed and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the device installed On a tennis ballthrowing machine.

FIG. 2 is a sectional view, on an enlarged scale, taken substantiallyalong the line 22 of FIG. 1.

FIG. 3 is a sectional view taken substantially along the line 3-3 ofFIG. 2.

FIG. 4 is a sectional view taken substantially alon the line 44 of FIG.2.

FIG. 5 is a sectional view esseentially the same as FIG. 4 showing thecam on top of the lobe thereby angling the path of the thrown ball.

FIG. 6 is a sectional view taken substantially along the line 66 of FIG.4.

FIG. 7 is an enlarged perspective view of the adjustable motor mount.

Referring now to the drawings the numeral 10 generally designates aconventional tennis ball throwing machine, while numeral 12 designatesthe oscillating mechanism therefor. The machine 10 can be any one of theconventional tennis ball throwing machines, and as such does notconstitute a part of this invention. The installation of the oscillatingmechanism 12 requires that the main support shaft 14 be cut in half nearthe lower end thereof, yielding a lower portion 16 and an upper portion18. A pivot ball 20 is inserted into the lower portion 16 to rest in thebottom thereof, and a pivot shaft 22 is inserted on top thereof. Theoutside diameter of the shaft 22 is slightly smaller than the insidediameter of the upper and lower portions 16 and 18 to provide arelatively tight pivotal axis therefor. The pivot shaft 22 extendsupwardly into the inside of the upper portion 18 and is fixed thereto,such as by welding, 50 that the upper portion 18 will be supported onthe pivot ball 20 and shaft 22 out of contact with the lower portion 16as indicated at 24. Thus, the basic swiveling function is providedbetween the oscillating head of the throwing machine and its base.

A cam assembly 26 is fixed to the lower portion of the main supportshaft 16 thereby forming the relatively stationary part of a cammingassembly. The cam assembly 26 has a main support plate 28, which isfixed to the lower portion 16 of the main support shaft by a spacerblock 30. The main support plate 28 is an elongated rectangular memberfastened to the block 30 at its relative midpoint, with a rollerassembly 32 mounted at one end. The assembly 32 has a main base block 34with two parallel extending members 36 thereon. A wheel 38 is journaledfor rotation between the members 36 by an axle 40 extendingtherebetween. Fixed to the opposite ends of the main support plate 28 isa spring retainer abutment 42 to keep the return spring aligned thereon.A cam return adjustment 44 is mounted on the main support plate 28susbtantially midway between the spacer block 30 and the roller assembly32. The cam return 44 has a threaded shank 46 which is received in athreaded opening 48 through the plate 28. Thus, the cam assembly 26 isfixed to the lower portion 16 of the main support shaft and therefore tothe base of the throwing machine, and is, as mentioned above, therelatively stationary part of the swivel assembly.

The cam follower assembly and drive mechanism 50 is attached to theupper portion 18 of the main support shaft and constitutes therelatively movable portion of the camming assembly. The cam followerassembly 50 has a main shaft 52 fixed to the upper shaft portion 18 intangential relationship thereto, as by welding, as indicated at 54. Themain shaft 52 is fixed on the shaft portion 18 on the side thereof onwhich the assembly 32 is affixed to the cam assembly. A cam followersprocket wheel 56 with teeth 57 around the circumference thereof isjournaled for rotation on the shaft 52 by a bearing 58 affixed to thecenter of the wheel 56. The diameter of the wheel 56 is sufiicient thatwhen journaled on the shaft 52 the outside or circumference of the wheelextends beyond the wheel 38, so that the wheel 38 may ride on the planarsurface of the cam follower sprocket wheel 56. The follower wheel 56 hasa ramplike lobe 60 thereon spaced near the circumference thereof to beengaged by the wheel 38. Thus, while the wheel 38 rides on the planarsurface of the follower sprocket 56 there is no relative movementtherebetween, but when the lobe 60 engages the wheel 38 the uppersection of the main support shaft and the elements mounted thereon wouldbe forced to rotate relative to the lower shaft and the cam mechanismattached thereto. A return arm 62 is fixed to the circumference of theupper portion 18 of the shaft, as by welding at 64, to extend in aposition substantially parallel to the main support plate 28. A springretainer abutment 66 is fixed to the free end of the return arm 62opposite the abutment 42 on the main support plate 28 of the cammechanism. An elongated coil return spring 68, whose ends fit over andengage the abutments 42 and 66 and are retained thereon, force thesupport plate 28 and return arm 62 away from each other therebymaintaining the follower and cam in an initial position or returning thefollower mechanism and the cam assembly to their initial position, asshown in FIG. 4. To provide an abutment to limit the return of the camfollower assembly to an initial position after the wheel 38 has gone offthe lobe 60 an arm 70 is fixed to the circumference of the upper portion18 of the main shaft in parallel relation to the plane of the sprocketwheel 56 and the return arm 62. The arm 70 is fixed on the same side ofthe main shaft as the shaft 52 so as to overlie the threaded end 46 ofthe cam return adjustment 44. In this way the return of the cam followerassembly can be limited by the engagement of the arm 70 with theaforementioned threaded end 46, which adjustment 44 can be advanced tothe point where it will hold the follower out of engagement with thewheel 38 and allow continuous volleying or serving in a straight line orbe advanced completely out of engagement with the arm 70 whereby thefull angular displacement of the cam lobe 60 will take place. A stop 71is fixed to the circumference of the upper portion 18 of the mainsupport shaft adjacent the return arm 62 in perpendicular relationshipthereby. The stop 71 limits the movement of the throwing mechanism whenthe wheel 38 engages the cam lobe 60 so that inertia thereof will notswivel the mechanism to cause collapse of the return spring 68 andcontact between support plate 28 and return arm 62.

The drive for the sprocket 56 is provided by taking power from thethrowing machine. As illustrated in FIG. 7, a motor mount assembly 72has a main support shaft 74 fixed to the circumference of the upperportion 18 of the main support shaft. A sleeve 76 whose inside diameteris slightly larger than the outside diameter of the support shaft 74 ismounted thereon and has a motor support plate 78 attached to thecircumference thereof. The motor support plate is fixed in any relativeposition to the support shaft 74 by an adjustment assembly 80 whichincludes an elongated threaded shaft or setscrew 82 with a handle 84thereon to facilitate tightening the threaded shaft or setscrew 82sufficiently to hold the motor support. The threaded shaft is engaged innut 86 which is welded to the circumference of the sleeve 76 tocooperate with a threaded opening 88 therein so that the threaded shaft82 extends through the nut 86 and the opening 88 in the wall of thesleeve 76 to engage the main shaft 74. A collar 90 is affixed to theshaft 74 near the free end thereof to prevent inadvertent removal of themotor mount assembly 72 from the shaft 74. The motor support plate 78 isprovided with elongated slots 92 to provide for adjustment of the motoracross the width of the plate as well as the rotational adjustmentabout, and longitudinal adjustment along, the shaft 74.

A motor 94 is mounted on the motor support plate 78 with two V-beltpulleys 96 and 98 mounted on the drive shaft thereof. The V-belt 100takes the power from either of the pulleys 96 and 98 and drives thethrowing mechanism. Therefore by extending the V-belt 100 around eitherpulley 96 or 98 the speed of the throwing machine can be varied. TheV-belt pulleys 96 and 98 are brought into alignment for use with theV-belt 100 by moving the motor mount assembly along the motor mountsupport shaft 94 to align the proper pulley, depending upon the speed ofthe throwing mechanism desired, with the V-belt 180. A shaft 102 isjournaled for rotation on the upper portion 18 of the main support shaftand has two sprockets 104 and 106 fixed together and mounted thereon forsimultaneous rotation, with the larger sprocket 104 a part of theoriginal throwing machine, and therefore geared down to the desiredspeed, with the smaller sprocket 106 attached thereto. A chain 108 goesaround the original sprocket 104 and drives it from the throwingmachine, thereby driving the sprocket 106 which in turn drives thesprocket 56 by a chain 110 which extends around the sprockets 56 and106.

As mentioned hereinabove, when the speed of the serve is increased byusing the large V-belt pulley to drive the throwing machine, the speedof the oscillation of the mechanism is increased accordingly, since themechanism is driven by the chains 108 and 110 from the mechanism andeach serve will be launched first in the straight ahead position and thenext serve will be released when the cam wheel 38 has engaged the lobe60 to deflect the serving machine. Thereby successive serves will beangulary displaced relative to one another.

As mentioned hereinabove, the motor 94 is the main drive motor of theball throwing mechanism and is fixed to the upper portion 18 of the mainsupport shaft with the follower mechanism so that the entire driveassembly with the chains and follower would rotate about the verticallyextending main support shaft. The operation of the mechanism then isreadily apparent, since the mechanism will operate when the machine isin use. The sprocket 104 or 106 rotates the sprocket 56 therebyperiodically bringing the cam lobe 60 into contact with the cam wheel38. The size of the sprocket 106 and the sprocket 56 is chosen so thattwo tennis balls are thrown for each rotation of the sprocket 56,thereby launching one ball in a straight ahead position and the otherball on the defiected position when the cam wheel is on the surface ofsprocket 56 and on top of the lobe 60, respectively. By adjusting stopmember 46, the degree of angular displacement of the path of travel ofthe ball may be adjusted, thus requiring a player using the device totake a single lateral step or any number of steps to return successiveballs. The invention as above set forth is a simple modification to anexisting machine or is easily incorporated into a new article ofmanufacture. The invention thus is a simple but unique device to beincorported in the tennis ball throwing machine which greatly improvesthe training that can be obtained through its use.

We claim:

1. In a ball throwing machine, an upright support member, a ballthrowing mechanism on the upper portion of the support member, saidsupport member having first and second vertically aligned spaced-apartsections, a swivel connection inserted between and connecting said firstand second sections, said first section being fixed and said secondsection being rotatable, a cam assembly fixed to said first section, acam follower assembly fixed to said second section, and means for movingsaid cam follower assembly with respect to the cam assembly so that thelatter will react with the cam follower assembly and cause relativehorizontal movement between the first and second sections of saidsupport and a horizontal movement of the ball throwing mechanism.

2. The device of claim 1 wherein the swivel connection comprises a tubeinserted in the first and second sections of said support member intelescoping relationship therewith and being fixed to said secondsection and an antifriction device positioned at the end of the tubebetween the tube and the bottommost end of the first section.

3. The device of claim 1 wherein the cam assembly comprises an elongatedsupport plate fixed at a point intermediate ends to said first sectionof said support member between the ends of said first section, [thereof]and a wheel journaled for rotation on one end of said support plate.

4. The device of claim 3 wherein said cam follower assembly includes anaxial disc cam follower journaled for rotation on said second section ofsaid support so that the surface thereof adjacent the circumference willengage the cam assembly [wheel].

5. The device of claim 4 having means acting between said sections tobias the follower disc into engagement with the cam assembly [wheelsurface].

6. The device of claim 5 wherein said means acting between said sectionsis a spring acting between the other end of the elongated support plateand an abutment on said second section of said support member.

7. The device of claim 6 wherein further means act between saidelongated support plate and said second section of said support to limitthe biased movement between said cam assembly and said cam followerassembly.

8. In combination, a ball throwing machine having a base, an uprightsupport fixed thereto, a ball throwing mechanism supported on the upperportion of said support in spaced relation above the base, the supportincluding a first section fixed to the base and a second uppervertically aligned section fixed to the ball throwing mechanism, aswivel joint between and connecting said first and second sections forallowing movement of the second section relative to the first section, acam follower assembly affixed to one of said sections and a cam assemblyfixed to the other of said sections whereby the reaction between the camassembly and cam follower assembly, when the latter is rotating, willmove the second section relative to the first section thereby angularlydisplacing the trajectory of a ball thrown by the mechanism.

9. The device of claim 8 wherein said support is tubular and the swiveljoint comprises a tube inserted in the tubular support in telescopingrelationship therewith and being fixed to said second section and anantifriction device positioned at the end of the tube between the tubeand the bottommost end of the first section.

10. The device of claim 8 wherein the cam assembly comprises anelongated support plate fixed at a point between its ends to said firstsection of said support and having a wheel journaled for rotation on oneend of said support plate.

11. The device of claim 9 wherein said cam follower assembly includes anaxial disc cam follower journaled for rotation on said second section ofsaid support so that the surface of said disc adjacent the circumferencethereof will engage the wheel.

12. The device of claim 11 having means acting between said first andsecond sections to bias the cam follower disc into engagement with thecam wheel.

13. The device of claim 12 wherein said disc surface has one projectionthereon to be engaged by said cam wheel.

14. The device of claim 13 wherein further means act between saidelongated support plate and said second section of said support to limitthe biased movement between said cam assembly and cam follower assembly.

15. The device of claim 14 including a drive means to rotate one of saidassemblies.

16. The device of claim 15 wherein said drive means includes a motorfixed to said second section in spaced relation to said cam followerassembly and means interconnecting said motor and said cam followerassembly to rotate said cam follower assembly.

17. The device of claim 16 wherein the means interconnecting the motorand cam follower assembly includes a chain received around teeth on thecircumference of said cam follower assembly and a sprocket driven bysaid motor.

18. In a ball throwing machine the improvement comprising:

A. a base frame;

B. means including a vertically oriented, elongated support member fixedto said frame having a first section and a second section disposed aboveand in substantial vertical alignment to said first section, said firstsection being rigidly fixed to said frame and supported against motionrelative thereto;

C. a ball throwing mechanism supported by said support member andrigidly fixed to said second section so as to be movable in unison withmovement of the second section;

D. coupling means mounted on said first section for supporting saidsecond section for oscillatory motion about a substantially verticallyoriented axis coincident with the vertically oriented axis of symmetryfor said first section; and

E. drive means connected to said support member for imparting to saidsecond section oscillatory motion about said substantially verticalaxis.

19. The improvement 0 claim 18 wherein said drive means includes a drivetrain comprising a means which is moved during rotation of the drivetrain to cause oscillatory motion of the second section to oscillatorymotion.

20. The improvement of claim 18 wherein said drive means includes a camassembly mounted on said first section, a cam follower assembly mountedon said second section in coacting engagement with said cam assembly,said oscillatory motion being imported to said second section inresponse to a coaction of said cam follower assembly with said camassembly.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,666,424 1/1954 Foster 1249 1,030,852 6/1912Huntley 124-9 1,403,151 1/1922 Diehl 74-25 2,441,053 5/1948 Wooster74-25 X 3,277,879 10/1966 Sayette l24-26 RICHARD C. PINKHAM, PrimaryExaminer W. R. BROWNE, Assistant Examiner US. Cl. X.R.

